Abstract

The development of the “Micro Solid-State Photonics” such as microchip, micro domain structure or grain boundary engineered ceramic lasers and quasi-phase matched devices, opens new horizon in laser systems. The microchip laser is attractive as compact, reliable, and efficient source of coherent radiation. It can provide excellent spatial mode quality and narrow linewidth [1], Recently attention has been directed toward the multi-stage fiber amplified system combined with O-switched microchip laser to increase the power to megawatt level with maintaining single mode properties to cause any interaction upon the material. As a coherence parameter of laser to cause any interaction upon the material, the brightness-temperature (T_B^*) with M²-factor should be discussed. By using the microchip structure, we have demonstrated the high brightness-temperature laser operation with the stand-alone configuration. Obtained peak power is close to 2 MW for energy of 0.95 mJ and duration of 480 ps pulse with highly beam quality (M² =1.05 and Δλ<5 pm) in a diode end-pumped passively Q-switched Nd:Y₃Al₅O₁₂ (Nd:YAG) microchip laser. Up to 0.14 PW/cm²-sr brightness and ~2×l0²⁰K brightness-temperature were obtained with 16 mW electrical average power supply. This value is already 10¹⁶ times higher than that of the Sun, 6,000K. Its extremely high brightness allows us the efficient nonlinear wavelength conversion, from the wavelength of 266 nm to ~200 μm generation, and the efficient material process such as micro-drilling even for the stainless steal [2], Here, LiB₃O₅ and ß-BaB₂O₄ crystals are used to generate the visible and ultra violet region by the higher order harmonics from Nd:YAG. For efficient optical parametric oscillation in mid-IR region, the periodically poled MgO doped LiNbO₃ (PPMgLN) devices were used. Also, THz parametric generation by the non-poled MgLN device reached to the far-IR (100~200 pm) region as shown in Fig. 1.

© 2007 IEEE